This invention relates to cartons made of foldable material and, in particular, to paperboard cartons for food products such as pizza.
Each year thousands of pizza businesses sell millions of hot pizzas for delivery and carry-out. The success of these businesses depends to an extent on the cost and functionality of the cartons used for packaging the product. Ideally, these cartons should be cost-effective, easy to use, stackable, and rigid and crush-resistant.
Prior art structure can be defined in terms of slanting-wall versus non-slanting-wall construction. A carton of slanting-wall construction has at least one wall disposed at a substantially oblique angle (i.e., either obtuse angle or acute angle) to the bottom panel. A carton of non-slanting-wall construction has all the walls disposed substantially perpendicular to the bottom panel. A carton having slanting-wall construction is sometimes called a xe2x80x9cslanting-wall carton.xe2x80x9d A carton having non-slanting-wall construction is sometimes called a xe2x80x9cnon-slanting-wall carton.xe2x80x9d
Slanting-wall cartons further can be divided into xe2x80x9call-slanting-wall cartonsxe2x80x9d and xe2x80x9csome-slanting-wall cartons.xe2x80x9d In an all-slanting-wall carton all the walls are slanting. In a some-slanting-wall carton at least one of the walls is slanting and at least one of the walls is substantially perpendicular to the bottom panel.
Slanting-walls also can be divided into two types: outward-slanting walls, which are disposed at an obtuse angle to the bottom panel, and inward-slanting walls, which are disposed at an acute angle to the bottom panel.
A possible advantage of an inward-slanting-wall carton is material-savings. A possible advantage of a non-slanting-wall carton is maximal stacking strength. Finally, a possible advantage of a some-slanting-wall carton having an inward-slanting wall and a perpendicular wall is a combination of both material-savings and stacking strength (which can be an important feature to a pizza delivery business).
Prior art structure also can be defined in terms of fastened versus non-fastened construction. A carton of fastened construction has at least one corner panel or corner flap permanently fastened to an adjacent panel or flap by means of glue, staple, or stitches. Conversely, a carton of non-fastened construction has no corner panels or corner flaps fastened to an adjacent panel or flap by means of glue, staple, or stitches. A carton having fastened construction is sometimes called a xe2x80x9cfastened carton.xe2x80x9d Similarly, a carton having non-fastened construction is sometimes called a xe2x80x9cnon-fastened carton.xe2x80x9d A possible advantage of a fastened carton is quick set-up. A possible advantage of a non-fastened carton is low-cost manufacture and price savings (a feature that""s highly important to most pizza businesses).
In addition, prior art structure can be defined in terms of full-length cover panel versus partial-length cover panel construction. A carton having full-length cover panel construction has a cover panel that extends from one wall substantially all the wall to an opposing wall or wall structure of the carton, whereby the cover panel overlies the entire cavity, or virtually the entire cavity, of the carton. A carton having partial-length cover panel construction has no full-length cover panel but, instead, most likely has one or more cover panels that each overlie only a portion of the cavity of the carton. A possible advantage of full-length cover panel construction is structural rigidity, or resistance to downward pressure, in the center of the cover panel (a feature that is very important to pizza delivery operations, where heavy objects like a liter bottle of soda are often carried on top of the pizza box).
Further, prior art can be defined in terms of stackable versus non-stackable construction. A carton of stackable construction has no stacking-impeding tabs projecting above the cover panel of the box (a stacking-impeding tab being one that would prevent the bottom panel of an upper box from fully contacting the cover panel of a lower box when the two boxes are in a stacked arrangement). A carton of non-stackable construction has one or more stacking-impeding tabs projecting above the top surface of the cover panel.
Finally, prior art structure can be defined in terms of rectangular versus non-rectangular cartons. A xe2x80x9crectangular cartonxe2x80x9d is one which has a substantially rectangular bottom panel and four wall panels. A xe2x80x9cnon-rectangular cartonxe2x80x9d is one which has a non-rectangular bottom panel and five or more wall panels. A possible advantage of some non-rectangular cartons is material savings.
The instant invention pertains to non-fastened cartons. The preferred embodiment of the invention also pertains to a particular structure of non-rectangular, some-slanting-wall carton of stackable construction having a full-length cover panel.
The prior art discloses the following cartons having at least one inward-slanting wall: Neumann U.S. Pat. No. 917,347 granted Apr. 6, 1909; Shapiro U.S. Pat. No. 1,141,076 granted May 25, 1915; Ikeda et al. U.S. Pat. No. 2,072,753 granted Mar. 2, 1937; Opler U.S. Pat. No. 3,253,769 granted May 31, 1966; Fox U.S. Pat. No. 3,361,329 granted Jan. 2, 1968; Brauner U.S. Pat. No. 4,339,068 granted Jul. 13, 1982; Hall U.S. Pat. No. 4,804,136 granted Feb. 14, 1989; Kuhn et al. U.S. Pat. No. 5,305,951 granted Apr. 26, 1994; Whitnell U.S. Pat. No. 5,603,450 granted Feb. 18, 1997; and Watanabe U.S. Pat. No. 5,669,552 granted Sep. 23, 1997. In addition, the prior art discloses Zion et al. U.S. Pat. No. 4,765,534 granted Aug. 23, 1988, which shows a carton having a curved wall that is inward-slanting at the ends but non-slanting (or substantially perpendicular) at the center. This curved wall provides no material savings over a non-slanting wall and this Zion et al. carton does not qualify as a slanting-wall carton.
In addition to the Zion et al. patent, which shows a non-rectangular carton, the prior art also discloses the following additional two non-rectangular cartons: Deiger U.S. Pat. No. 5,000,374 granted Mar. 19, 1991, and Philips et al. U.S. Pat. No. 5,702,054 granted Dec. 30, 1997. The Philips et al. carton is currently being used by Domino""s Pizza as its pizza carton. A problem with all of these non-rectangular cartons is a tendency to collapse when the cover panel is pushed in a rearward direction relative to the bottom panel. This rearward pushing action on the cover panel can sometimes inadvertently occur during delivery, particularly when multiple cartons are stacked. In the Philips et al. carton the rearward pushing action on the cover panel results in the rear ends of the left and right cover side flaps sliding past the ends of the rear wall, resulting in a total collapse of the carton. It would be desirable to have a structure that prevents this from happening.
All of the above-cited prior art have one or more drawbacks as applied to delivery/carry-out pizza operations. Specifically, Shapiro, Fox, Brauner, Whitnell, and Watanabe are fastened cartons. Neumann, Ikeda et al., Opler, Brauner, Kuhn et al., Whitnell, and Watanabe are all-slanting-wall cartons (i.e., having no non-slanting walls). Fox, Hall, and Kuhn et al. have only partial-length cover panels. Hall and Whitnell are not stackable (i.e., they have one or more stacking-impeding tabs). And Zion et al., Deiger, and Philips et al. have no material-saving inward-slanting walls at all. Plus Zion et al., Deiger, and Philips et al. are prone to collapse when a rearward pushing action is applied to the cover panel.
So, there has remained a need for a pizza carton that (a) achieves a material savings (derived from inclusion of one or more inward-slanting walls and/or a partial-height cover front flap), (b) has low manufacturing cost (derived from non-fastened construction), (c) has maximal stacking strength (derived from inclusion of one or more non-slanting walls), (d) has a collapse-proof cover (derived from inclusion of a full-length cover panel), and (e) has stackability (derived from avoidance of stacking-impeding tabs).
In conclusion, it would be highly desirable to provide a pizza carton that overcomes the above-cited drawbacks and satisfies the above-described need. Nothing in the prior art does that. However, my invention does.
My invention is a non-fastened food carton that can incorporate one or more of the following features:
1) A slanting-wall-enabling cover side flap structure comprising a cover side flap hingedly attached to a cover panel at a cover side flap fold line and a corner flap hingedly attached to an end of the cover side flap at a fold line disposed at an oblique angle to the cover side flap fold line, and with the corner flap disposed between an end wall and an end of a side wall of the carton;
2) A bottom panel that has a front-to-rear length that""s longer than a left-to-right width of the bottom panel and a full-length cover panel that has a front-to-rear length that""s shorter than the bottom panel""s front-to-rear length, with the carton including both inward-slanting and non-inward-slanting walls;
3) In relation to a pizza contained within the carton, a bottom panel having a front-to-rear length that""s at least six millimeters longer than the diameter of the pizza and a full-length cover panel having a front-to-rear length that""s at least eight millimeters shorter than the diameter of the pizza, with the carton also including both inward-slanting and non-inward-slanting walls;
4) A stack of inward-slanting-wall pizza cartons that have no stacking-impeding tabs projecting beyond the cover panel;
5) A non-rectangular structure similar to that disclosed in Philips et al. U.S. Pat. No. 5,702,054 but with a cover front flap that has a height that""s substantially shorter than the height of the front wall; and
6) A rigidizing rear wall in combination with left and right cover side flaps disposed exterior to left and right side walls, in which the rear wall has a left-to-right width at least six millimeters longer than the left-to-right width of the cover panel.
My invention typically would be used for packaging relatively flat food products such as pizza; however, it could take other forms for other food packaging purposes, as well.
A complete understanding of the invention can be obtained from the detailed description that follows.
The object of my invention is a material-saving food carton that sacrifices nothing in way of functionality and strength.
The advantage of my invention is cost savings for the box manufacturer and/or pizzeria owner without any attendant operational inconvenience or deterioration of package integrity.